First, remember our friend Spinosaurus from Jurassic Park 3? Easily the coolest creature in a very uneven creature feature, the onscreen predator was just as much at home swinning up on people submerged as it was fighting T. rex. Scientists have debated for a long time how aquatic Spinosaurus was. Did it swim, or was it just an occasional wader? The fragmentary nature of available skeletal material didn't answer that. Now we know: Spinosaurus apparently was equipped for a crocodile-like lifestyle, tethered to the land but hunting fish, reptiles, and other dinosaurs in the rivers and shallows, snatching animals in the water or perhaps ambushing them as they came down to drink (which must have been hard with that sail). We know this because we have good fossils of the tail now, and it's a crocodile-like tail, flattened side-to-side, suited for propulsion for an animal that also shared the crocodilian tendency toward short legs and (we think) webbed feet. It was the first true swimmer we know of among the dinosaurs. The key fossils came from Morocco and were unearthed in 2017-18.
Coverage here from Nat Geo
Spinosaurus at the George S. Eccles Dinosaur Park-Museum, Odgden, Utah Rea;;y cool, but we didn't know about the tail. Photo by Matt Bille, 2018.
About unearthing dinosaurs. I've always wondered if some ancient traveler saw a Spinosaurus eroding out of a cliff and saw the sail as a pair of wings folded up. "So that's what a dragon looks like!"
The biggest dinosaur search of all time, called Mission: Jurassic, is on in Northern Wyoming, near the famed Morrision Formation. Here's a fascinating story about the riches being uncovered and how one scientist has committed the next 20 years of his life to excavating the site.
Allosaurus, a common denizen of the Mission: Jurassic site and the Morrison Formation (photo origin unknown)